Partial zero-emissions vehicle

A partial zero emissions vehicle, in the United States, is an automobile that has zero evaporative emissions from its fuel system, has a 15-year (or at least 150,000-mile) warranty on its emission-control components, and meets SULEV tailpipe-emission standards.[1]

Advanced Technology PZEVs (AT-PZEVs) are at least as "clean" as regular PZEVs and either use no gasoline or have much greater fuel efficiency because they are hybrid electric vehicles.

CARB also prepared a TZEV (Transitional ZEV, formerly Enhanced AT-PZEV) category for plug-in hybrids (PHEVs) and hydrogen vehicles. (Not to be confused with Hydrogen Fuel Cell Electric Vehicles which are certified as ZEV or Zero Emission Vehicles.) In addition to the 15 year or 150,000 mile warranty for zero evaporative (fuel system) emissions, and SULEV tailpipe emissions, PHEVs must also warranty their traction battery for 10 years or 150,000 miles.[2] While PHEVs and hydrogen internal combustion engine vehicles exist, none meet this stringent standard.

Except some hybrids and alternative-fuel vehicles, PZEVs do not inherently offer consumers any kind of incentives other than the extended emissions warranty. In particular, PZEV vehicles do not automatically qualify for the hybrid vehicle tax credit or for the "clean air vehicle" decal that used to allow hybrid car drivers to use car-pool lanes.[3]

PZEVs do, however, provide benefits to the originating automaker in the form of ZEV credits. Automakers must have a certain number of ZEV credits based on the number of vehicles they sell annually in California, with exceptions granted for small volume manufacturers. Without ZEV credits, automakers cannot sell in California. Automakers with excess credits can sell them. No automaker has ever missed compliance.[4]